About CalculatorPOP
I'm Sroush, and I build, test, and fact-check every calculator on this site myself before it goes live. I'm from Norway, and CalculatorPOP grew out of a habit I can't seem to shake: turning ideas into small, useful tools in my free time. This site is that habit pointed at something other people can use for free, with no account and no catch.
Why I Built This Site
I like making things. Outside of my day-to-day work, I'm usually building some small tool, script, or side project just to see if I can get it right. CalculatorPOP started the same way: a few calculators I built for myself, cleaned up and put online because I couldn't find versions I liked using elsewhere. Most of what's out there is either buried under ads that hide the result, or it doesn't explain where the numbers come from.
My goal with this site is simple. Every calculator should be fast, clear, and genuinely useful, and every article next to it should explain the math honestly, including what it can't tell you. No sign-up walls, no paywalled results, no dark patterns. Just tools I'd want to use myself.
My Background
I hold a dual master's degree, one in Finance and one in Computer Science, which is a strange combination on paper but a natural one for a site like this. Finance trained me to think carefully about how numbers are defined and where they can mislead you if you're not paying attention. Computer science taught me how to turn that thinking into something you can click and use. Every calculator on this site sits somewhere between those two disciplines: a real formula, sourced properly, wrapped in an interface that doesn't get in your way.
Ten Years in the Gym, and Just as Many Spent Reading About It
I've trained consistently for more than a decade, and somewhere along the way it turned into more than a hobby. A good chunk of my free time goes into reading peer-reviewed research and clinical guidelines on training and nutrition, and watching lectures and breakdowns from coaches and researchers I trust, rather than taking advice from whoever is loudest that week on social media. It's less about chasing every new trend and more about slowly building a habit of checking claims against the evidence before I believe them.
That habit is exactly what shapes the health and fitness calculators here. They're not thrown together from a single blog post. Each one is built against the same standards you'd find in official guidance from bodies like the CDC, WHO, and NHLBI, and I test the underlying math across unit conversions and edge cases before anything ships.
How I Build and Check Each Calculator
Every calculator follows roughly the same process before it's allowed on the site.
Start from an official, trusted source for the underlying formula or ranges, such as the CDC, WHO, NHLBI, or NHS, and confirm the figures directly rather than copying them from another website.
Build the calculator itself, then stress-test the math by hand across unit conversions and boundary values to make sure it holds up, not just on the examples I first tried.
Write the article that sits next to it, explaining what the result means, what it leaves out, and when to take it with caution, with sources cited at the bottom.
Revisit the page when guidelines change. Health and nutrition guidance is updated periodically, and I'd rather correct a page than leave outdated numbers live.
What's Coming Next
Health, fitness, and language-learning calculators are where this site started, and they'll stay a priority. But they're not the ceiling. I'm building toward a much wider set of tools, including finance calculators, everyday math tools, and a few just-for-fun calculators that don't need a serious excuse to exist. If it's useful, or just genuinely fun to use, it fits here somewhere.
If a calculator saved you time, sharing this page is the easiest way to say thanks.
CalculatorPOP is free, ad-supported, and built by one person who checks the math by hand. Passing the link to a friend, a classmate, or your gym group helps far more than you'd think.